Support housing for exhaust gas turbochargers

ABSTRACT

A support housing for the fastening of the exhaust gas turbochargers of an internal-combustion engine is provided. The support housing encloses a hollow space which is used for receiving the turbines of the exhaust gas turbochargers while the compressors are situated outside the hollow space. In order to simplify the manufacturing and assembly and to reduce the costs, bearing housings of the exhaust gas turbochargers are integrated in the support housing. The manufacturing and the assembly may also be simplified and rendered less expensive by the fact that the support housing is divided into two symmetrical housing parts along a plane extending through the perpendicular axis in the center of the support housing. In this case, the two housing parts are preferably constructed to be centrically symmetrical with respect to the central perpendicular axis.

BACKGROUND AND SUMMARY OF THE INVENTION

The invention relates to a support housing for exhaust gas turbochargerswhich can be placed on an internal-combustion engine and, moreparticularly, to a support housing for at least two exhaust gasturbochargers which can be placed on an internal-combustion engine. Theexhaust gas turbochargers are each constructed with two blade wheelsarranged on a common shaft. One blade wheel is arranged in a compressorhousing and the other is arranged in a turbine housing. The common shaftis in each case disposed in a bearing housing arranged between thecompressor housing and the turbine housing. The turbine housings of theexhaust gas turbochargers form flow spaces which each comprise a spiralduct, an adjoining, radially interior blade wheel duct and an axiallydirected outlet duct. The support housing is constructed as a box-typesupporting device for the exhaust gas turbochargers which contains ahollow space and on which the exhaust gas turbochargers are fastened.The compressor housings are arranged outside the hollow space and theturbine housings are arranged inside the hollow space. Recesses forpassing-through the shafts of the exhaust gas turbochargers are providedin the walls of the support housing as well as openings for feeding andremoving the exhaust gases to and from the turbine housings.

A support housing of the above described type is known from GermanPatent document DE 34 39 738 C2. In the case of this known superchargedinternal-combustion engine, the turbine housing of the exhaust gasturbocharger is arranged in a hollow space formed by a support housing.The compressor housing of the exhaust gas turbocharger is disposedoutside the hollow space. For the purpose of fastening, the exhaust gasturbocharger is received, together with its bearing housing, in acylindrical recess of the lateral wall of the support housing. Theexhaust gas turbocharger is fastened on the support housing by usingscrews. This cylindrical recess for receiving the bearing housing isformed by two semicircular recesses having an upper and a lower part onthe edges. On the edges of the upper and lower part, the support housingis composed. When the upper part is taken off, the exhaust gasturbocharger can be inserted in the recess at the lower part forassembly purposes. The assembly can be completed when the upper part isfitted back on.

The bearing housing of an exhaust gas turbocharger according to GermanPatent document DE 35 32 695 C1, is at the same time, constructed as anengine support arranged between an elastic bearing and theinternal-combustion engine. In this dual function as a bearing housingand as an engine support, a savings in components is achieved which hascorresponding advantages. However, it is not always possible ordesirable to arrange an exhaust gas turbocharger in an area of theinternal-combustion engine in which the bearing housing is used as anengine support.

In the case of a supercharged internal-combustion engine according toGerman Patent document DE 30 05 655 C2, a support housing placed on theinternal-combustion engine, which is composed of a lower part and anupper part, is also used for the space-saving fastening of exhaust gasturbochargers. In this case, the turbine housings of the exhaust gasturbochargers and the corresponding exhaust gas pipes are arrangedinside a hollow space formed by the support housing. The compressorhousings with the corresponding charge air pipes are situated outsidethe hollow space. The exhaust gas turbochargers, which are arranged withhorizontal axes, are disposed in the area of the bearing housings insemi-cylindrical recesses of the edge areas of the upper and the lowerpart. The upper and lower parts rest against one another in a horizontaldividing joint. When the upper part is removed, an exhaust gasturbocharger can be inserted for assembly purposes in the recess on thebottom part and, after the upper part is fitted back on, can be fastenedby means of screws on the upper and the lower part.

In the case of the example in German Patent document DE 30 05 655 C2,wherein a charger arrangement consists of two groups for two-stagecharging, the support housing encloses four turbine housings which arearranged with respect to a perpendicular axis of the support housing ina centrically symmetrical manner in a support housing. The supporthousing is also constructed in a centrically symmetrical manner. It isconsidered a disadvantage of the known support housing construction thatit consists of differently constructed components which are expensive tomanufacture because correspondingly different tools must be madeavailable for the manufacturing. For the case of a conventional castconstruction different form tools are required. These different toolsare expensive.

There is therefore needed a simplified manufacturing and mounting for asupport housing, while achieving a space-saving construction which thusmakes it less expensive.

These needs are achieved according to the present invention by providinga support housing for at least two exhaust gas turbochargers which canbe placed on an internal-combustion engine. The exhaust gasturbochargers are each constructed with two blade wheels arranged on acommon shaft. One blade wheel is arranged in a compressor housing andthe other is arranged in a turbine housing. The common shaft is in eachcase disposed in a bearing housing arranged between the compressorhousing and the turbine housing. The turbine housings of the exhaust gasturbochargers form flow spaces which each comprise a spiral duct, anadjoining, radially interior blade wheel duct and an axially directedoutlet duct. The support housing is constructed as a box-type supportingdevice for the exhaust gas turbochargers which contains a hollow spaceand on which the exhaust gas turbochargers are fastened. The compressorhousings are arranged outside the hollow space and the turbine housingsare arranged inside the hollow space. Recesses for passing-through theshafts of the exhaust gas turbochargers are provided in the walls of thesupport housing as well as openings for feeding and removing the exhaustgases to and from the turbine housings. The bearing housings of theexhaust gas turbochargers are integrated into the walls of the supporthousing.

In this manner, the support housing is therefore constructed such that,not only can the exhaust gas turbochargers be fastened on it and theexhaust gas turbine housings be arranged in a hollow space, but alsothat it contains the bearing housing in which the shafts of the exhaustgas turbochargers are disposed. It also contains the ducts required forthe lubrication of the bearings and is used as a protective housing forthe bearing components. The bearing housings are therefore no longerseparate components so that the number of required components is reducedwhereby the manufacturing and assembly is naturally simplified.

It is particularly advantageous for the support housing to be developedas a cast construction with molded-in bearing housings. In order for thesupport housing to be accessible from the interior side, it is composedof at least two parts. In this case, it is advantageous not to place thedividing joint in areas in which an exhaust gas turbocharger is to befastened. This is done so that none of the bearing housings of theexhaust gas turbochargers are divided. This construction is favorablefor the assembly. In this case, it is advantageous for the supporthousing to be divided in a plane in parallel to a perpendicular axis.The exhaust gas turbochargers can then be fully mounted on the housingparts before the housing parts are assembled to form the supporthousing. It is further advantageous for a symmetrical support housingthat the number of components be limited further, and the manufacturingbe made still less expensive. This is because both housing parts, i.e.,two symmetrical parts, for a support housing may, in each case, beproduced using the same tool. The housing parts rest against one anotherin a dividing joint which is situated in a plane extending in thecentral perpendicular axis of the support housing. When such symmetricalhousing parts are used, the tool costs are reduced because fewerdifferent tools are required. At the same time, the mounting and storageis simplified as a result of the same components being used for bothhousing parts.

The support housing can be constructed in a particularly space-savingmanner when the housing parts consist of two housing parts which arecentrically symmetrical with respect to the perpendicular axis and onwhich the exhaust gas turbochargers are also arranged in a centricallysymmetrical manner.

Two groups of two-stage exhaust gas turbochargers can be arranged in aspace-saving manner while the mounting is simple if one high-pressureand one low-pressure exhaust gas turbocharger is assigned to eachhousing part of the support housing. The longitudinal axes of theseturbochargers are situated at an acute angle with respect to one anotherwhen viewed in the direction of the perpendicular axis.

Other objects, advantages and novel features of the present inventionwill become apparent from the following detailed description of theinvention when considered in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of a support housing according to theinvention with a mounted exhaust gas turbocharger including a bearinghousing integrated in the support housing;

FIG. 2 is a top view of two groups of exhaust gas turbochargers arrangedin a support housing for two-stage charging, while the support housingis cut along the sectional lines II--II illustrated in FIG. 3 below atthe level of the passages for receiving the charger.

FIG. 3 is a view in the direction of the sectional line III--IIIillustrated in FIG. 2 extending through the dividing plane of one halfof the support housing without the exhaust gas turbocharger.

DETAILED DESCRIPTION OF THE DRAWINGS

The support housing 10 illustrated in the sectional view of FIG. 1 isdeveloped as a cast construction. The support housing consistsessentially of two housing parts 11, 11'. The housing parts 11, 11' areconnected with one another on flanges 113 using screws. The supporthousing 10, which is placed on an internal-combustion engine (notshown), forms a hollow space in which the housing of a turbine 107 of anexhaust gas turbocharger 102 is arranged. A compressor 106 of an exhaustgas turbocharger 102 is situated outside the hollow space formed by thesupport housing 10. The support housing 10 is constructed using a doublewall in which cooling water circulates. For passing-through exhaust gaspipes, which are connected with the inlet and the outlet of the turbine107, the support housing 10 is provided with corresponding passages.

A bearing housing 108 of the exhaust gas turbocharger 102 is molded intoa wall of the support housing 10. For receiving a bearing support ring103, a cylindrical receiving opening is molded into the support housing10. In the bearing support ring 103, slide bearing bushings 104 of theshaft 105 are arranged. The slide bearing bushings 104 are connectedwith the blade wheels of the compressor and of the turbine. An axialbearing 112 is used for receiving axial forces. The compressor 106 andthe turbine 107 are fastened to the support housing 10 using screws.Furthermore, the support housing 10 contains an inlet duct 109 and anoutlet duct 110 for lubricating oil which is used to lubricate thebearings. The outlet duct 110 is connected with a pipe 111 which returnsthe lubricating oil into a collector pot of the internal-combustionengine. The bearings of the exhaust gas turbocharger 102 are cooled bythe appropriate construction of the hollow cooling spaces in the supporthousing 10.

Naturally, the support housing 10 may also be used for the fastening ofseveral exhaust gas turbochargers 1, 2, 1', 2', as illustrated in FIG.2. The construction of the support housing 10 with the integratedbearing housings 108 permits a simple assembly. Costs are saved in themanufacturing and storage of this construction because of the reducednumber of components used. It is particularly advantageous to constructthe support housing from symmetrical housing parts with severalsymmetrically arranged exhaust gas turbochargers, as described in thefollowing with respect to FIGS. 2 and 3.

The turbocharger arrangement illustrated in FIG. 2 in a top viewconsists of two groups of exhaust gas turbochargers 1, 2 and 1', 2' forproviding a two-stage charging. The two groups are arranged centricallysymmetrically with respect to one another and with respect to a centralperpendicular axis. The high-pressure turbines 4, 4' and thelow-pressure turbines 6, 6' of the exhaust gas turbochargers arearranged inside the support housing 10. The support housing 10 is formedof two housing parts 11, 11' which rest against one another along adividing joint 9. The dividing joint 9 extends in a plane which issituated in the central perpendicular axis of the support housing 10.The housing parts 11, 11' have a centrically symmetrical constructionwith respect to the central perpendicular axis of the support housing10. In the area of their bearing housings 16, 17, 16', 17', the exhaustgas turbochargers 1, 2, 1', 2' are inserted in passages of the supporthousings 10 and are screwed to the passages on steps. The supporthousing is illustrated in various sectional planes so that the passageswhich are situated at different levels are visible. By way of passagesformed in the bottom of the support housing 10, the engine exhaust gasesarrive at the high-pressure turbines 4 and 4'. By way of the outletconnections 7, 7', the exhaust gases will then reach the spiral housingsof the low-pressure turbines 6, 6'. By way of the intake connections 18,18', the charge air is sucked into the low-pressure compressors 5, 5'and is then, by way of the charge air pipes 13, 13' and the charge aircoolers 14, 14', guided to the inlet connections of the high-pressurecompressors 3, 3'. By way of pipes 12, 12' and other charge air coolers(not shown), the compressed charge air reaches the combustion spaces ofthe internal-combustion engine.

FIG. 3 is a view of the housing part 11' of the support housing 10viewed in the direction of the sectional line III--III of FIG. 2. Thesectional line III--III is situated along the dividing joint 9. Theexhaust gas turbochargers are not shown. In the lateral wall, thepassages are shown for receiving the bearing housings of the exhaust gasturbochargers. However, the passages are not shown with the bearinghousing integrated in the support housing. In the bottom, a passage issituated which is shown in an offset sectional plane and into which apipe 8' is inserted. The pipe 8' is connected with the inlet connectionof the high-pressure turbine 4'. On the top side of the support housing,a passage is provided for an exhaust gas pipe for the removal of theexhaust gas flow leaving the exhaust gas turbines. According to theoperating condition of the internal-combustion engine, the enteringexhaust gas can be blocked by way of the flap 15'.

The housing parts 11' and 11 of the support housing 10 are screwed toone another on a surrounding flange by way of screws. The supporthousing 10 has hollow spaces in which the cooling water of theinternal-combustion engine circulates. However, these hollow spaces arenot shown in FIG. 2. It is considered to be an advantage of theperpendicular division of the support housing that the support housingcan be joined together from two symmetrical housing parts. The symmetryof the components has the advantage of reducing manufacturing costs anda simplifying assembly.

Another reduction of components takes place when, as described inconnection with FIG. 1, the bearing housings 16, 17, 16', 17' of theexhaust gas turbochargers in FIG. 2 are integrated in the supporthousing 10.

In order to ensure that the bearing housings in the support housing arenot divided, the support housing preferably is to be divided into twohousing halves in such a manner that the dividing joint extends outsidethe areas in which the bearing housings are arranged.

Although the invention has been described and illustrated in detail, itis to be clearly understood that the same is by way of illustration andexample, and is not to be taken by way of limitation. The spirit andscope of the present invention are to be limited only by the terms ofthe appended claims.

We claim:
 1. Support housing for at least two exhaust gas turbochargersarrangeable on an internal-combustion engine, the exhaust gasturbochargers each having two blade wheels arranged on a common shaft,one of said two blade wheels being arranged in a compressor housing andthe other of said two blade wheels being arranged in a turbine housing,comprising:a bearing housing arranged between the compressor housing andthe turbine housing having the common shaft disposed therein for eachexhaust gas turbocharger; wherein the turbine housings of the exhaustgas turbochargers form flow spaces, each of said flow spaces including aspiral duct, an adjoining, radially interior blade wheel duct, and anaxially directed outlet duct; wherein the support housing is constructedas a box-type supporting device forming a hollow space therein, saidexhaust gas turbochargers being fastened on said box-type supportingdevice such that the compressor housings are arranged outside the hollowspace and the turbine housings are arranged inside the hollow space;recesses for in walls of the support housing, said common shafts of theexhaust gas turbochargers extending through said recesses; openingsprovided in said walls for feeding and removing exhaust gases to andfrom the turbine housings; wherein the bearing housings of the exhaustgas turbochargers are formed integrally in one-piece with said walls ofthe support housing.
 2. Support housing according to claim 1, whereinthe support housing comprises at least two housing parts, a dividingjoint extending between said housing parts being located so as not toextend through said recesses in said walls for receiving the exhaust gasturbochargers.
 3. Support housing according to claim 2, wherein thesupport housing is divided in planes extending in parallel to an axisextending in a direction of a common surface normal line from planesdefined by longitudinal axes of said exhaust gas turbochargers, andwherein the exhaust gas turbochargers are fastened to lateral walls ofsaid box-type supporting device.
 4. Support housing according to claim1, wherein the support housing is divided into two substantiallysymmetrical housing parts along a plane extending through an axisextending in a direction of a common surface normal line from planesdefined by longitudinal axes of said exhaust gas turbochargers. 5.Support housing according claim 1, wherein the support housing is formedof two housing parts centrically symmetrical with respect to an axisextending in a direction of a common surface normal line from planesdefined by longitudinal axes of said exhaust gas turbochargers, theexhaust gas turbochargers being arranged on said centrically symmetricalhousing parts in a centrically symmetrical manner with respect to thecentral perpendicular axis.
 6. Support housing according to claim 2,wherein exhaust gas turbochargers for a two-stage charging are assignedto each of the housing parts respectively, and wherein in the directionof an axis extending in a direction of a common surface normal line fromplanes defined by longitudinal axes of said exhaust gas turbochargers,horizontally extending longitudinal axed of the exhaust gasturbochargers are each disposed at an acute angle with respect to oneanother.
 7. A support for exhaust gas turbochargers which is arranged onan internal-combustion engine, the exhaust gas turbochargers each havingtwo blade wheels arranged on a common shaft, one of said two bladewheels being arranged in a compressor housing and the other of said twoblade wheels being arranged in a turbine housing, comprising:a supporthousing constructed as a box-type supporting device forming a hollowspace therein, said exhaust gas turbochargers being fastened on saidbox-type supporting device such that the compressor housings arearranged outside said hollows space and the turbine housings arearranged inside said hollow space; and wherein said box-type supportingdevice has a bearing housing portion formed integrally therewith forsupporting the common shaft of each of said exhaust gas turbochargers.